Somethings I'm not sure about

Well i just finished khII but there are a few things i have queries and annoyances about

Topic 1:
From my understanding organisation XIII was trying to get hearts from the heartless sora kills. Then they were returning these hearts to the nobodies. So how is this a bad thing and why were sora and company trying to stop them?

Topic 2:
What would happen if i went into wisdom form just before the 1000 heartless battle. Would i still be in it when the battle begins?

topic 3:
Not so much a question but, i found the first time you visit each world really annoying. Theres no original plot like in KH1 where unexpeced things keep happening. But in kh2 it just takes the story from the films and summarises them, no surprises or anything, except a few character changes and heartless taking place of henchmen. As a result the only interesting parts in the game for me were the worlds for films i havent seen and worlds like hollow bastion and twighlight town. I personally found this very frustrating, did anyone else feel this way or is it just me? Is there some deeper meaning?

Further more about plot, Sora seems to continually forget that he's looking for Riku and such. In KH1 he did this but got slapped in the face by Riku when he said, why are you asking about them (Donald and goofy) when you should be asking about her (Kairi) or something, and its like oh snap. But now finding Riku is just sort of something that will happen eventually and no one seems to care about Sora's short attention span. I find this annoying as well.

Sora wanted to stop Organization XIII because he disapproved of their methods. While they only wanted their hearts back, they were pretty nasty in their methods of achieving that goal. Whether or not their goals can be justified doesn't change the fact that their methods cannot.

I've no idea about changing to Wisdom form right before the 1,000 heartless battle. As I've never heard of that working before (but heard plenty of complaints about not being able to do it, I imagine the answer is no.

The Disney worlds in Kingdom Hearts are rarely the highlights of the game. The best parts of Kingdom Hearts are always occurring in original worlds. KH tends to throw a lot of plot at the player at the beginning, middle, and end with Disney filler between. Organization XIII played a far less active role during the first half of the game than the villains did in the original, but their involvement kicked up a notch after the attack on Hollow Bastion.

As far as Sora's search for Riku, I never really got the impression that it ever really left his mind. As a keyblade master, Sora has a lot to take care of, and between fighting heartless and taking on the nobodies, it's not hard to believe that he'd get regularly sidetracked.

I have actually gone into a form right before the 1000 heartless battle, just to check and see what happens. In the immediate scenes, Sora keeps his clothes. But in the scene right before the fight, Sora is in his original form holding the Kingdom Key, always. It doesn't matter if you were in a form or what keychain you have equipped, always normal Sora with the Kingdom Key. Also, Donald and Goofy will have their original weapons as well. Sora wouldn't be able to keep his form since neither Donald nor Goofy were there anyway.